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1986 (189)
1Author    PaulineA. Lizotte, JonathanE. PoultonRequires cookie*
 Title    Identification of (jR)-Vicianin in D avallia trichomanoides Blume  
 Abstract    D edicated to P rofessor H ans Grisebach on the occasion o f his 60th birthday D avallia trichom anoides, Cyanogenic G lycoside (/?)-Vicianin The cyanogenic glycoside o f young fronds and fiddleheads o f the fern Davallia trichom anoides Blum e was identified as (Ä)-vicianin (the ß-vicianoside o f (7?)-mandelonitrile) by acid and enzym ic hydrolysis, 'H -N M R and 13C -N M R spectroscopy, and by com parison with an authentic sam ple isolated from Vicia angustifolia seeds. 
  Reference    Z. Naturforsch. 41c, 5 (1986); received February 2/May 28 1985 
  Published    1986 
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 Identifier    ZNC-1986-41c-0005 
 Volume    41 
2Author    JanM. Steyns, JanV B RederodeRequires cookie*
 Title    Differential Regulation of Two Genes Controlling the Biosynthesis of Isovitexin 7-O-Galactoside in Silene Plants  
 Abstract    D epartm ent o f Population and Evolutionary B iology, U niversity o f U trecht, D edicated to P rofessor Hans G risebach on the occasion o f his 60th birthday Silene, Isovitexin 7-O -G alactosylation G en es, 0 7 g and Xgal, Differential Regulation The expression o f the allelic isovitexin 7-O -glycosylation genes g G (transfer of glucose) and g X (transfer o f xylose) was studied in cotyledons, rosette leaves, stem leaves and petals o f Silene plants. These studies revealed that g G is expressed in all ontogenetic stages, whereas its allele g X is only expressed in the petals. In the vegetative parts o f g X individuals 7-O -xylosylation is replaced by 7-O -galactosylation. The possibility that g X encodes an enzym e activity that catalyzes different reactions in the petals and the vegetative parts resulting in the accumulation o f the 7 -0 -xyloside and the 7-O -galactoside respectively, has been disproved. It is shown that there are two different enzym es catalyzing the biosynthesis o f isovitexin 7-O -galactoside. These 7-O -galactosyl-transferase activities differ with respect to heat inactivation, pH optim um , flavone acceptor specificity and M ichaelis-M enten enzym e kinetic parameters. The genes controlling these enzyme activities are regulated differentially, with gene 0 7 g (described previously by Steyns et al. [11]), expressed in the cotyledons and the rosette leaves and X g a l in the stem leaves and petals. 
  Reference    Z. Naturforsch. 41c, 9 (1986); received April 1 1985 
  Published    1986 
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 Identifier    ZNC-1986-41c-0009 
 Volume    41 
3Author    ClaudeA. Ndary, RagaiK. IbrahimRequires cookie*
 Title    Biosynthetic Capacity of Stachys Seedlings for Verbascoside and Related Caffeoyl Derivatives  
 Abstract    D edicated to P rofessor H ans G risebach on the occasion o f his 60th birthday Stachys, L abiatae, V erbascoside, Stachyoside, Caffeoyl Derivatives The caffeoyl derivatives o f Stachys leaves (Labiateae) were identified as chlorogenic acid, verbascoside and stachyoside. The latter com pound, reported here for the fist tim e, was show n to be a verbascoside derivative containing an extra glucose residue attached to C-2, C-3 or C-4 of rham nose. Cotyledonary leaves o f Stachys accumulate high levels (8 —16 ^mol/g dry tissue) o f the three caffeoyl derivatives; all o f which decrease significantly in amount during plant growth. Intact organs o f the seedling were shown to efficiently incorporate the label from different precursors into caffeoyl derivatives. The biosynthesis o f both verbascoside and stachyoside from labelled precursors revealed that the caffeoyl m oiety was exclusively labelled from phenylalanine or cinnamic acid, whereas the 3,4-dihydroxyphenylethanol moiety was labelled from tyrosine, and better from tyramine. 
  Reference    Z. Naturforsch. 41c, 18 (1986); received June 4/August 8 1985 
  Published    1986 
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 Identifier    ZNC-1986-41c-0018 
 Volume    41 
4Author    M. Argot Schulz, G. Ottfried WeissenböckRequires cookie*
 Title    Isolation and Separation of Epidermal and Mesophyll Protoplasts from Rye Primary Leaves — Tissue-Specific Characteristics of Secondary Phenolic Product Accumulation  
 Abstract    D edicated to P rofessor H ans G risebach on the occasion o f his 60th birthday Secale cereale L ., Epiderm al, M esophyll Protoplasts, Localization o f Flavonoids We have develop ed a technique for the large-scale isolation o f epidermal and m esophyll proto­ plasts, as w ell as the vascular strands, o f rye primary leaf blades. Separation o f the two types o f protoplasts has been successful only from leaves harvested at the end o f a 13-h light period, when chloroplasts were enriched in starch. The occurrence o f different flavonoid com pounds, and am ounts, in epiderm al and m esophyll protoplasts can be used as criteria for protoplast purity and viability since C -glucosylflavone O-glycosides are characteristic o f epiderm al protoplasts whereas flavone O -glucuronides and an-thocyanins are typical o f m esophyll protoplasts. Several non-flavonoid phenolic com pounds are found only in the epiderm al protoplast. These patterns o f secondary product accum ulation reflect the high tissue specificity o f the rye leaf. 
  Reference    Z. Naturforsch. 41c, 22 (1986); received June 10 1985 
  Published    1986 
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 Identifier    ZNC-1986-41c-0022 
 Volume    41 
5Author    W. Alter Gräwe, D. Ieter StrackRequires cookie*
 Title    Partial Purification and Some Properties of l-Sinapoylglucose: Choline Sinapoyltransferase ("Sinapine Synthase") from Seeds of Raphanus sativus L. and Sinapis alba L  
 Abstract    A cyltransferase, H ydroxycinnam ic A cid Conjugates, G lucose Ester, Phenylpropanoid M etabol­ ism, R aphanus, Sinapine, Sinapis H ydroxycinnam oyltransferases which catalyze the formation of O-sinapoylcholine (sinapine) using l-0-sinapoyl-ß-D -glucose as acyl donor have been isolated from seeds o f radish (Raphanus sativus L. var. sativu s) and mustard (Sinapis alba L.) and purified 420-and 293-fold, respectively. The enzym es ("sinapine synthase") had apparent molecular weights o f about 60,000 daltons and show ed highest activities at pH 7.2 and 7.6, respectively, at 45 °C with apparent energies o f activation at 53 kJ m ol-1. There were no requirements for divalent cations or sulfhydryl reagents. The apparent K m's o f the radish and mustard enzym es were 0.48 and 0.71 m M for 1-sinapoylglu-cose and 5.3 and 6.5 mM for choline, respectively. The 1-feruloyl-and 1-p-coum aroylglucose were found to tard). 6-0-Sinapoylglucose, 3-0-sinapoylfructose, 1-0-accepted as donors. 
  Reference    Z. Naturforsch. 41c, 28—33 (1986); received June 11 1985 D edicated to 
  Published    1986 
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 Identifier    ZNC-1986-41c-0028 
 Volume    41 
6Author    L-D Ouri, PaulM. DewickRequires cookie*
 Title    Biosynthesis of the Furanoacetylene Phytoalexin Wyerone in Vicia faba  
 Abstract    D edicated to P rofessor H ans G risebach on the occasion o f his 60th birthday Biosynthesis, P hytoalexin, Furanoacetylene, W yerone, Vicia faba Feeding experim ents using l3C -labelled sodium acetate precursors in CuCl2-treated broad bean (Vicia faba) cotyledons have dem onstrated that the furanoacetylene phytoalexin wyerone is biosynthetically derived from seven intact acetate units. A further experim ent using sodium [2H 3]acetate indicated the head of the chain, and showed the chain is analogous to that o f a fatty acid precursor, any chain shortening process from postulated C 18 precursors occurring from the carboxyl end. Incorporations o f oleate and linoleate were, how ever, regarded as insufficient to prove the involvem ent o f these com pounds in the biosynthetic pathway. 
  Reference    Z. Naturforsch. 41c, 34 (1986); received June 24 1985 
  Published    1986 
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 TEI-XML for    default:Reihe_C/41/ZNC-1986-41c-0034.pdf 
 Identifier    ZNC-1986-41c-0034 
 Volume    41 
7Author    KeithR. Davis, AlanG. Darvill, Peter Albersheim, Anne DellRequires cookie*
 Title    Host-Pathogen Interactions XXX. Characterization of Elicitors of Phytoalexin Accumulation in Soybean Released from Soybean Cell Walls by Endopolygalacturonic Acid Lyase  
 Abstract    D edicated to P rofessor H ans Grisebach on the occasion o f his 60th birthday Erwinia, P hytoalexins, Elicitors, Endopolygalacturonic Acid Lyase, O ligogalacturonides Endopolygalacturonic acid lyase, purified from the phytopathogenic bacterium, Erwinia carotovora, induces phytoalexin accumulation in soybean (Glycine max L .) cotyledons. This pectin-degrading enzym e releases heat-stable elicitors o f phytoalexin accumulation from soybean cell walls, citrus pectin, and citrus sodium polypectate. The most elicitor-active m olecules ob­ tained by treating soybean cell walls with endopolygalacturonic acid lyase have been purified and characterized. The cell-w all-derived elicitors are a -l,4-lin k ed oligogalacturonides with degrees o f polym erization o f eight to tw elve residues. The m olecules with the highest specific elicitor activity were identified as a -l,4 -lin k e d deca-and undecagalacturonides that contained 4,5-unsaturated galactosyluronic acid at the nonreducing termini. 
  Reference    Z. Naturforsch. 41c, 39 (1986); received June 24 1985 
  Published    1986 
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 Identifier    ZNC-1986-41c-0039 
 Volume    41 
8Author    BerndL. Aber, H. Ans-, H. Errm, Ann Kiltz, Nikolaus AmrheinRequires cookie*
 Title    Inhibition of Phenylalanine Ammonia-Lyase in vitro and in vivo by (l-Amino-2-phenylethyl)phosphonic Acid, the Phosphonic Analogue of Phenylalanine  
 Abstract    Phenylalanine A m m onia-L yase, (l-A m ino-2-phenylethyl)phosphonic and -phosphonous A cids, A m in o A cid M etabolism , Fagopyrum esculentum The phosphonic analogue of L-phenylalanine, (/?)-(l-am ino-2-phenylethyl)phosphonic acid (A P E P), inhibits buckwheat phenylalanine ammonia-lyase (P A L) com petitively with a K t value o f 1.5 |iM. The K, value for the (S)-enantiom er is 11.6 jj,M. The corresponding values for the enantiom ers o f the phosphonous analogue are 35 and 205 |u.m , respectively. A P E P inhibits the light-induced synthesis o f anthocyanin in hypocotyls of etiolated buckwheat seedlings and causes a specific increase in the endogenous phenylalanine concentration in buckwheat hypocotyls as well as other plant tissues. Kohlrabi seedlings develop normally in the presence o f A P E P , while their anthocyanin content is greatly reduced. These results indicate that A P E P inhibits P A L in vivo. 
  Reference    Z. Naturforsch. 41c, 49 (1986); received June 25 1985 D edicated to 
  Published    1986 
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 Identifier    ZNC-1986-41c-0049 
 Volume    41 
9Author    JeremyM. Boniwell, V. Ernon, S. ButtRequires cookie*
 Title    Flavin Nucleotide-Dependent 3-Hydroxylation of 4-Hydroxyphenylpropanoid Carboxylic Acids by Particulate Preparations from Potato Tubers  
 Abstract    Potato Tubers, Solanum tuberosum , 4-H ydroxyphenylpropanoid Carboxylic A cid 3-Hydroxyla-tion, Phenolase Particulate preparations from potato tubers, extracted in 4 mM 2-m ercaptoethanol, catalyze the 3-hydroxylation o f 4-hydroxyphenylpropanoid carboxylic acids, including p-coum aric acid and tyrosine, in the presence o f N A D H (or N A D P H) and F A D (or FM N); ascorbate could not substitute for these electron donors. A m ong a range of 4-hydroxylated C6—C2 and C6—Q com ­ pounds tested, only 4-hydroxyphenylacetic acid and p-cresol were hydroxylated. The hydroxylase was sensitive to KCN and diethyldithiocarbam ate and show ed som e features of phenolase hy-droxylation, but no D O P A oxidase nor chlorogenic acid oxidase activity was exhibited under these conditions. It is suggested that the phenolase com plex, which is confined to potato tuber particles, in w hole or part catalyzes the hydroxylation. 
  Reference    Z. Naturforsch. 41c, 56 (1986); received June 26 1985 
  Published    1986 
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 Identifier    ZNC-1986-41c-0056 
 Volume    41 
10Author    Reiner Brödenfeldt, HansM. OhrRequires cookie*
 Title    Use of Immunotitration to Demonstrate Phytochrome-Mediated Synthesis de novo of Chalcone Synthase and Phenylalanine Ammonia Lyase in Mustard Seedling Cotyledons  
 Abstract    D edicated to Professor H ans G risebach on the occasion o f his 60th birthday Sinapis alba, Enzym e Induction by Phytochrom e, Im m unotitration, Chalcone Synthase, Phenyl­ alanine Am m onia Lyase 
  Reference    Z. Naturforsch. 41c, 61 (1986); received June 28/Septem ber 10 1985 
  Published    1986 
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 Identifier    ZNC-1986-41c-0061 
 Volume    41 
11Author    JamesA. Connelly, EricE. ConnRequires cookie*
 Title    Tyrosine Biosynthesis in Sorghum bicolor: Isolation and Regulatory Properties of Arogenate Dehydrogenase  
 Abstract    D edicated to P rofessor H ans G risebach on the occasion o f his 60th birthday A rogenate D ehydrogenase, Prephenate D ehydrogenase, Tyrosine Biosynthesis, Shikimate Path­ way, Sorghum bicolor The conversion o f prephenic acid to tyrosine can occur by two different routes: (a) oxidative decarboxylation (prephenate dehydrogenase) follow ed by transamination (aromatic am inotrans­ ferase); (b) transam ination o f prephenate forming the non-aromatic amino acid arogenic acid (prephenate am inotransferase) follow ed by oxidative decarboxylation (arogenate dehydroge­ nase). High activity o f arogenate dehydrogenase was found in extracts of etiolated sorghum seedlings, while no evidence of prephenate dehydrogenase was observed. A rogenate dehydrogenase from sorghum eluted, with high recovery o f activity (93%), as a single peak on D E A E -cellu lose chromatography. The enzym e was strongly inhibited by tyrosine but was unaffected by phenylala­ nine, prephenate, or tryptophan. Kinetic analysis showed that tyrosine inhibition was com petitive with arogenate and that the K t for tyrosine (61 (.i m) was much smaller than the K m for arogenate (350 |j .m) . The properties o f arogenate dehydrogenase indicate that this enzym e is important in the regula­ tion o f tyrosine biosynthesis in sorghum. Strong inhibition o f the enzym e by tyrosine m ay indicate that arogenate is a branch point in the shikim ate pathway in plants and therefore arogenate may be a precursor to phenylalanine and the num erous phenylpropanoid secondary m etabolites deriv­ ed from phenylalanine. 
  Reference    Z. Naturforsch. 41c, 69 (1986); received June 28 1985 
  Published    1986 
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 Identifier    ZNC-1986-41c-0069 
 Volume    41 
12Author    DanielL. Siehl, JamesA. Connelly, EricE. ConnRequires cookie*
 Title    Tyrosine Biosynthesis in Sorghum bicolor: Characteristics of Prephenate Aminotransferase  
 Abstract    Prephenate: G lutamate A m inotransferase, Tyrosine Biosynthesis, Sorghum bicolor, Shikimate Pathway, A rogenate A stable activity which transfers the am ino group from glutam ate to prephenate was extracted from 4-day old etiolated shoots o f sorghum. The activity was retained on D E A E cellulose and eluted as a single peak. Prephenate aminotransferase co-eluted with a very abundant a-ketogluta-rate: aspartate am inotransferase, but heating at 70 °C resulted in loss of a-k etoglu tarate: aspar­ tate activity with nearly full retention o f prephenate: glutam ate aminotransferase activity. The heated enzym e displayed high affinity and specificity for prephenate. A m ong 7 donors tested, only glutamate, and aspartate at less than 20% the rate with glutamate, supported prephenate aminotransferase activity. In the reverse direction, a reaction rate comparable to that in the forward direction was unchanged as the concentration of a-ketoglutarate was reduced from 1.0 to 0.09 m M . The apparent K m for arogenate was 0.8 m M . The forward reaction was unaffected by the inclusion o f tyrosine, phenylalanine or tryptophan. T ogether with the discovery o f arogenate dehydrogenase in sorghum [3], these data indicate that, in the sorghum plant, tyrosine derives from prephenate by transamination and arom atization. rather than the reverse sequence. 
  Reference    Z. Naturforsch. 41c, 79 (1986); received June 28/August 14 1985 
  Published    1986 
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 Identifier    ZNC-1986-41c-0079 
 Volume    41 
13Author    EckhardW. Ollenweber, Ingrid Schober, PiaD. Ostal, D. Agm Ar Hradetzky, FranciscoJ A Rriaga-G, Iner, George YatskievychRequires cookie*
 Title    Flavonoids and Terpenoids from the Exudates of Some Baccharis Species  
 Abstract    Baccharis (C om positae, A stereae), Aerial Parts, Exudates, F lavonoid A glycones, Terpenoids Seven species o f the genus Baccharis have been analyzed for flavonoid aglycones. Many known methylated flavones, flavonols and flavanones were identified. From B. sarothroides, two novel flavonols were isolated and elucidated as 5,7,4'-trihydroxy-3,6,8-trim ethoxyflavone and its methyl ether, 5,4'-dihydroxy-3,6,7,8-tetram ethoxyflavone. Previous literature reports on flavonoids in Baccharis are summarized and their distribution and external occurrence is discussed. O ne novel diterpene and one rare triterpene were found in the terpenoid fractions that constitute m ost o f the exudate material in these and other C om positae. 
  Reference    Z. Naturforsch. 41c, 87 (1986); received June 28/August 27 1985 
  Published    1986 
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 Identifier    ZNC-1986-41c-0087 
 Volume    41 
14Author    MichaelH. Ebei, G.Erhard Brandner, HeinzK H Ochkeppel, D. Ietm, G. BraunRequires cookie*
 Title    Transformation-Related Cellular Protein p53: Increased Level in Untransformed Rat Cells Following Treatment with the Tumorpromoter, T etradecanoylphorbol-Acetate  
 Abstract    D edicated to P rofessor H ans G risebach on the occasion o f his 60th birthday p53 Induction, 12-0-T etradecanoylphorbol-13-acetate, Phorbolester, Rat Cells 12-0-T etradecanoylphorbol-13-acetate (T P A , 100 ng m l-1), a tumor prom oting phorbol ester, is able to induce enhanced levels o f the transform ation-associated cellular antigen p53 in normal rat2 cells which had not been previously initiated by a carcinogen. p53 was estim ated in ethanol-fixed treated cells on m icrotiter plates with E L ISA using the m onoclonal antibody Pab 1620 [EM BO J. 7, 1485, (1984)]. Induction o f p53 was confirm ed by im m unoblotting. This effect o f TPA is an additional phenotypic characteristic o f tumor cells which can be induced by TPA in untransformed rodent cells. 
  Reference    Z. Naturforsch. 41c, 94 (1986); received July 3 1985 
  Published    1986 
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 Identifier    ZNC-1986-41c-0094 
 Volume    41 
15Author    B. Ernhard Kniep, PeterF M Ühlradt, G. Esellschaft Für, B. Iotechnologische Forschung, M. Bh, W. Ascheroder, EgRequires cookie*
 Title    Glykosphingolipid-Analyse von menschlichen myeloischen Leukämien Glycosphingolipid Analysis of H um an Myeloid Leukemias  
  Reference    Z. Naturforsch. 41c, 100 (1986); received July 3/August 22. 1985 
  Published    1986 
  Keywords    birthday D ifferentiation, G lycosphingolipids, Leukem ia Cells, High Performance Liquid Chromatogra­ phy French-Am erican-British Classification 
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 Identifier    ZNC-1986-41c-0100 
 Volume    41 
16Author    A.Rtur Pfitzner, Leo Polz, Joachim StöckigtRequires cookie*
 Title    Properties of Vinorine Synthase — the Rauwolfia Enzyme Involved in the Formation of the Ajmaline Skeleton  
 Abstract    Rauwolfia serpentina B enth., Cell Suspension Cultures, Vinorine Synthase, Ajm aline Skeleton Vinorine synthase, a key enzym e in the formation o f the R auw olfia alkaloid ajmaline and its derivatives, has been isolated from Rauw olfia serpentina cell suspension cultures. The new enzy­ me has been 160-fold purified and characterized in detail. The synthase catalyses a single step in the biosynthesis of ajmalan alkaloids by the acetyl-coenzym e A and 16-epi-vellosim ine dependent formation of vinorine, which shows the basic ajmaline skeleton. B esides a characteristic substrate specificity the major properties o f the enzym e are a relatively high pH optimum (pH 8.5), a temperature optimum o f 35 °C, an isoelectric point o f pH 4.4, and a relative m olecular weight of 31000 ± 8%. The apparent K m values for 16-epi-vellosim ine and acetyl-coenzym e A were 19.4 [xm and 64 |xm resp. for the formation o f vinorine. Kinetic data o f the catalysed reaction indicate that 17-deacetylvinorine is not involved as a free interm ediate during the vinorine biosyn­ thesis. Vinorine was proved by in vivo feeding experim ents to be the biosynthetic precursor o f the alkaloids in the final stages o f the ajmaline pathway, vom ilenine (21-hydroxyvinorine), 1 7 -0 -acetylnorajmaline and 17-O -acetylajm aline. 
  Reference    Z. Naturforsch. 41c, 103 (1986); received July 3. 1985 D edicated to 
  Published    1986 
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 Identifier    ZNC-1986-41c-0103 
 Volume    41 
17Author    K.-O Vollmer, W. Klemisch, A. Von, H. OdenbergRequires cookie*
 Title    High Performance Liquid Chromatography Coupled with Radioactivity Detection: A Powerful Tool for Determining Drug Metabolite Profiles in Biological Fluids  
 Abstract    D edicated to P rofessor Hans G risebach on the occasion o f his 60th birthday Radioactivity Flow-Through D etector, Coupling o f HPLC with Continuous Radioactivity D e te c ­ tion, Drug M etabolism , H igh Perform ance Liquid Chromatography High perform ance liquid chrom atography coupled with continuous radioactivity detection rep­ resents an advancem ent in drug m etabolism research. Using radioactive substances labelled in biologically stable positions, all m etabolites can be specifically detected by radioactivity m easure­ ment. Thus no clean-up o f biological fluids is required prior to HPLC. This can prevent artefact formation from unstable m etabolites, reduces recovery problems and facilitates quantitation. Separation o f highly polar and unpolar m etabolites is possible in a single chromatographic run using gradient elution and reversed phase materials. This technique is also w ell-suited for prepara­ tive isolation and purification o f m etabolites for subsequent structure elucidation. Various m etabolite profiles o f drugs labelled with carbon-14 or tritium are shown. M etabolites o f the follow ing drugs are presented: norfenefrine, etozolin, thym oxam ine, naloxon e, and levobunolol. We review the general m ethodology and report our experience with this technique. In principle, this technique may be useful for all biological systems in which tracer techniques are applied. 
  Reference    Z. Naturforsch. 41c, 115 (1986); received July 3/O ctober 11 1985 
  Published    1986 
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 Identifier    ZNC-1986-41c-0115 
 Volume    41 
18Author    Chi-KitW. At, Paul Steffens, M. Einhart, H. ZenkRequires cookie*
 Title    Partial Purification and Characterization of S-Adenosyl-L-Methionine: Norreticuline N-Methyltransferases from Berberis Cell Suspension Cultures  
 Abstract    Isoquinoline A lkaloids, Norreticuline, R eticuline, Biosynthesis, Plant Cell Culture Tw o new N-m ethyltransferases (NM T-I and N M T-II) were found to occur in Berberis vulgaris cell suspension cultures. O ne o f these enzym es (N M T-I) was partially purified (100-fold) and characterized. This enzym e is specific for tetrahydrobenzylisoquinoline alkaloids and S-adenosyl-L-methionine serves as the methyl donor. The apparent m olecular weight of the enzym e is 68,000. The pH optimum o f the enzyme is 7.6, the temperature optimum 35 °C. Apparent K M values for (/?)-tetrahydropapaverin as substrate were 0.2 m M and for SAM 0.04 m M . The preparation o f the same type o f enzym e from B. wilsoniae var. subcaulialata was utilized as an efficient enzym atic system for the synthesis o f stereochem ically pure (/?)-as well as (S)-reticuline labelled with tritium or 14C at the N —CH 3 group. Enzym es catalyzing this type o f reactions are nam ed S-adenosyl-L-m eth ion in e: norreticuline N-m ethyltransferases. 
  Reference    Z. Naturforsch. 41c, 126 (1986); received July 3 1985 D edicated to 
  Published    1986 
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 Identifier    ZNC-1986-41c-0126 
 Volume    41 
19Author    Ralf-M Ichael Schmidt, H. Erm, Ann Pape, M. Atthias JunackRequires cookie*
 Title    Biosynthesis of 4-Formyl-4-imidazoIine-2-on, the Heterocyclic Base of Nikkomycin X  
 Abstract    D edicated to P rofessor Hans G risebach on the occasion o f his 60th birthday N ikkom ycin, B iosynthesis, 4-Form yl-4-im idazoline-2-on, Streptom yces tendae, H istidine M etabolism The nucleoside-peptide antibiotic nikkomycin X contains the unusual heterocyclic base 4-form yl-4-im idazoline-2-on. Investigations on the biosynthesis o f this base were accom plished in a resting cell system which was optim ized in respect to nikkomycin production. Incorporation experim ents with [2-l4C ]adenine, [8 -14C ]adenine, [2-14C]glycine, [2-14C]uracil, [U -14C ]histidine, and [2-14C]histidine revealed that only [2-14C ]adenine, [U -14C]-and [2-14C]hist-idine were specifically incorporated into nikkom ycin X. A n incorporation experim ent with [2-13C ]adenine resulted in a 31-fold enrichment o f the carbon atom 2 o f 4-form yl-4-im idazoline-2-on. These results show that the heterocyclic base o f nikkomycin X is a product o f the histidine biosynthetic pathway. 
  Reference    Z. Naturforsch. 41c, 135 (1986); received July 5/August 19 1985 
  Published    1986 
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 Identifier    ZNC-1986-41c-0135 
 Volume    41 
20Author    Bernd Schneider, H. Orst-R, Alfred Obert Schütte, PreissRequires cookie*
 Title    Metabolism of the Plant Growth Regulator tE)-[3H]2-Ethylhex-2-enoic Acid in Hordeum vulgare  
 Abstract    A kadem ie der W issenschaften der D D R , Institut für Biochem ie der Pflanzen, 4020 H alle/Saale, W einberg 3, D eutsche D em okratische R epublik D edicated to Professor Hans G risebach on the occasion o f his 60th birthday M etabolism , Plant Growth R egulator, H ydroxylation, C onjugation, Structural Elucidation The metabolism o f (£')-[3H ]2-ethylhex-2-enoic acid (E H A) was studied in excised seedlings of barley (H ordeum vulgare). It was rapidly taken up from the nutrient medium. The m etabolites, isolated by extraction with m ethanol, separated and purified by TLC and H PLC , were identified by enzym atic, chemical, and spectrom etric m ethods, especially 'H -N M R spectroscopy. The time course o f m etabolism during 6 , 12, 24, 48, and 72 h is presented, indicating intercon­ versation reactions. A rapid conjugation with glucose was observed, decreasing in concentration again after longer time periods in favour o f disaccharide esters, higher conjugates, and a hy­ droxylation product which was present in free and conjugated form. 
  Reference    Z. Naturforsch. 41c, 141 (1986); received July 8. 1985 
  Published    1986 
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 Identifier    ZNC-1986-41c-0141 
 Volume    41 
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